IRA’s and 401(k)’s can be good investment opportunities depending on the investment opportunities available to you in any given account.
The main benefit to both is that they are tax advantaged accounts. One possible pitfall is a poor choice of investments.
Two of the largest, most reputable financial institutions are Vanguard and Fidelity. Between the two, Vanguard has the reputation as the lowest cost investment provider.
Investing is a very broad subject. If you have additional specific questions, we will be glad to help.